156 



P> I T U A R Y. 



Ernst Abbe. 

 Born, Jan. 23, 1840; Died, Jan. U, 1905. 



ERNST Abbe — the illustrious Honorary Member of our Society, to 

 whom, more than to any other man, the perfection of the modern 

 Microscope is due — was the son of a foreman in a spinning mill at 

 Eisenach, in the Grand Duchy of Saxe-Weimar. Evincing talent 

 at an early age, he was sent to the universities of Jena and 

 Gbttingen, at the latter of which he took his degree, his thesis 

 being on the " Mechanical Equivalent of Heat." After passing a 

 short time at Frankfort-on-tke-Main as a Privatdocent,* he was, at 

 the age of twenty-three, appointed by the Jena University as 

 Lecturer on Mathematics, Physics and Astronomy, on the strength 

 of a treatise on the " Theory of Errors." Three years later he was 

 approached by Carl Zeiss, and induced to enter his firm as scientific 

 adviser. Thus began one of the most fruitful periods of progress in 

 the annals of optics. Carl Zeiss was a philosophical instrument 

 maker of Jena, whose business in those days was of but very 

 modest proportions. Imbued, however, with the necessity of 

 placing the construction of optical instruments, and especially of 

 Microscopes, on a more scientific basis, he looked around him for 

 suitable help. Experts on the subject being unavailable, he had to 

 find some one possessed of the necessary qualifications to become 

 one, and with the necessary force of character to prosecute his work 

 in the face of difficulties. That great obstacles would have to be 

 surmounted Carl Zeiss appears to have been fully aware, especially 

 as his first attempt to secure scientific guidance in putting Micro- 

 scope construction on a proper theoretical basis had been a failure, 

 and had led to his competitors recommending their Microscopes by 

 saying, "They were not like those made at Jena," In his second 

 choice of a coadjutor he was more fortunate, for Ernst Abbe proved 

 himself eminently qualified for the work. Not more than two 

 years had elapsed when, in 18G8, at the age of twenty-eight, Abbe 

 introduced his method of Microscope construction, consisting in the 

 complete theoretical determination beforehand of the required data. 

 Thenceforth the old haphazard trial-and-error methods of making 

 objectives were completely discarded. 



* A Privatdocent, for which we have no exact equivalent, is a university lecturer 

 qualifying for a professorship. 



